Digital Signal Processing Reference
In-Depth Information
6.
Build a watch by expanding the counter circuit to count seconds, hours, and minutes. The
two pushbuttons reset and start the watch.
7.
Replace the lpm_counter0 logic with a VHDL or Verilog counter design, simulate the
design, and verify operation on the FPGA board. Read Chapter 5 and note the example
counter design in section 6.10.
8.
Draw a schematic, develop a simulation, and download a design to the FPGA board that
uses the LCD displays for outputs and the DIP switch for input, to test the 74161 4-bit
TTL counter function found in the /others/maxplus2 symbol library. Use the DIP or slide
switch to provide four inputs for a parallel load of the count. Use a debounced pushbutton
input for the clock. Use the second pushbutton for the load input.
9.
Draw a schematic, develop a simulation, and download a design to the FPGA board to
test the following functions that can be created with the MegaWizard:
LPM_ADD_SUB:
a 2-bit adder/subtractor; test the add operation
LPM_ADD_SUB:
a 2-bit adder/subtractor; test the subtract operation
LPM_COMPARE:
compare two 2-bit unsigned numbers
LPM_DECODE:
a 4 to 16-bit decoder
LPM_CLSHIFT:
a 4-bit shift register
LPM_MULT:
a 2-bit unsigned multiply
The LPM megafunctions require several parameters to specify bus size and other various
options. For this problem, do not use pipelining and use the unregistered input options.
Refer to the online help files for each LPM function for additional information. In the
enter symbol
window, use the megawizard button to help configure LPM symbols. Use
the FPGA boards switches for four inputs as needed and display the output in hex on the
two seven-segment displays. Use a debounced pushbutton input for the clock, if one is
required. Use the second pushbutton for a Clear or Reset input. Use the timing analyzer
to determine the worst-case delay time for each function.
10.
Draw a schematic and develop a simulation to test the LPM_ROM megafunction. Create
a sixteen word ROM with eight data bits per word. Specify initial values in hex for the
ROM in a memory initialization file (*.mif) file. The contents of each memory location
should be initialized to four times its address. See MIF in the online help for details on
the syntax of a MIF file. Enter the address in four switches and display the data from the
ROM in the two seven-segment LEDs or the LCD. Determine the access time of the
ROM.
